USB serial: update the console driver

AlanStern · Live-CD User · commit 7bd032dc2793 · 2009-09-19T13:13:42.000-07:00
This patch (as1292) modifies the USB serial console driver, to make it
compatible with the recent changes to the USB serial core.  The most
important change is that serial-&gt;disc_mutex now has to be unlocked
following a successful call to usb_serial_get_by_index().

Other less notable changes include:

	Use the requested port number instead of port 0 always.

	Prevent the serial device from being autosuspended.

	Use the ASYNCB_INITIALIZED flag bit to indicate when the
	port hardware has been initialized.

In spite of these changes, there's no question that the USB serial
console code is still a big hack.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
diff --git a/drivers/usb/serial/console.c b/drivers/usb/serial/console.c
@@ -16,6 +16,7 @@
 #include <linux/slab.h>
 #include <linux/tty.h>
 #include <linux/console.h>
+#include <linux/serial.h>
 #include <linux/usb.h>
 #include <linux/usb/serial.h>
 
@@ -63,7 +64,7 @@ static int usb_console_setup(struct console *co, char *options)
 	char *s;
 	struct usb_serial *serial;
 	struct usb_serial_port *port;
-	int retval = 0;
+	int retval;
 	struct tty_struct *tty = NULL;
 	struct ktermios *termios = NULL, dummy;
 
@@ -116,13 +117,17 @@ static int usb_console_setup(struct console *co, char *options)
 		return -ENODEV;
 	}
 
-	port = serial->port[0];
+	retval = usb_autopm_get_interface(serial->interface);
+	if (retval)
+		goto error_get_interface;
+
+	port = serial->port[co->index - serial->minor];
 	tty_port_tty_set(&port->port, NULL);
 
 	info->port = port;
 
 	++port->port.count;
-	if (port->port.count == 1) {
+	if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) {
 		if (serial->type->set_termios) {
 			/*
 			 * allocate a fake tty so the driver can initialize
@@ -168,25 +173,30 @@ static int usb_console_setup(struct console *co, char *options)
 			kfree(termios);
 			kfree(tty);
 		}
+		set_bit(ASYNCB_INITIALIZED, &port->port.flags);
 	}
 	/* Now that any required fake tty operations are completed restore
 	 * the tty port count */
 	--port->port.count;
 	/* The console is special in terms of closing the device so
 	 * indicate this port is now acting as a system console. */
 	port->console = 1;
-	retval = 0;
 
-out:
+	mutex_unlock(&serial->disc_mutex);
 	return retval;
-free_termios:
+
+ free_termios:
 	kfree(termios);
 	tty_port_tty_set(&port->port, NULL);
-free_tty:
+ free_tty:
 	kfree(tty);
-reset_open_count:
+ reset_open_count:
 	port->port.count = 0;
-	goto out;
+	usb_autopm_put_interface(serial->interface);
+ error_get_interface:
+	usb_serial_put(serial);
+	mutex_unlock(&serial->disc_mutex);
+	return retval;
 }
 
 static void usb_console_write(struct console *co,
